<template>
  <div class="app-container">
    <div>
      <!--查询表单-->
      <el-form :inline="true" class="demo-form-inline">
        <!-- 所属分类：级联下拉列表 -->
        <!-- 一级分类 -->
        <el-form-item>
          <el-select
            v-model="searchObj.subjectParentId"
            placeholder="请选择"
            @change="subjectLevelOneChanged">
            <el-option
              v-for="subject in subjectNestedList"
              :key="subject.id"
              :label="subject.title"
              :value="subject.id"/>
          </el-select>
          <!-- 二级分类 -->
          <el-select v-model="searchObj.subjectId" placeholder="请选择">
            <el-option
              v-for="subject in subSubjectList"
              :key="subject.id"
              :label="subject.title"
              :value="subject.id"/>
          </el-select>
        </el-form-item>
        <!-- 标题 -->
        <el-form-item>
          <el-input v-model="searchObj.title" placeholder="课程标题"/>
        </el-form-item>
        <!-- 讲师 -->
        <el-form-item>
          <el-select
            v-model="searchObj.teacherId"
            placeholder="请选择讲师">
            <el-option
              v-for="teacher in teacherList"
              :key="teacher.id"
              :label="teacher.name"
              :value="teacher.id"/>
          </el-select>
        </el-form-item>
        <el-button type="primary" icon="el-icon-search" @click="initCourseList()">查询</el-button>
        <el-button type="default" @click="resetData()">清空</el-button>
      </el-form>
    </div>
    <div>
      <!-- 表格 -->
      <el-table
        v-loading="listLoading"
        :data="list"
        element-loading-text="数据加载中"
        border
        fit
        highlight-current-row
        row-class-name="myClassList">
        <el-table-column
          label="序号"
          width="50"
          align="center">
          <template slot-scope="scope">
            {{ (page - 1) * limit + scope.$index + 1 }}
          </template>
        </el-table-column>
        <el-table-column label="课程信息" width="400" align="center">
          <template slot-scope="scope">
            <div class="info">
              <div class="pic" v-if="scope.row.cover !== null && scope.row.cover !== ''">
                <img :src="scope.row.cover" alt="scope.row.title" width="80px">
              </div>
              <div v-else>
                无封面信息
              </div>
              <div class="title">
                <a href="">{{ scope.row.title }}</a>
                <p>{{ scope.row.lessonNum }}课时</p>
              </div>
            </div>
          </template>
        </el-table-column>
        <el-table-column label="创建时间" align="center">
          <template slot-scope="scope">
            {{ scope.row.gmtCreate.substr(0, 10) }}
          </template>
        </el-table-column>
        <el-table-column label="发布时间" align="center">
          <template slot-scope="scope">
            {{ scope.row.gmtModified.substr(0, 10) }}
          </template>
        </el-table-column>
        <el-table-column label="价格" width="100" align="center" >
          <template slot-scope="scope">
            {{ Number(scope.row.price) === 0 ? '免费' :
            '¥' + scope.row.price.toFixed(2) }}
          </template>
        </el-table-column>
        <el-table-column prop="buyCount" label="付费学员" width="100" align="center" >
          <template slot-scope="scope">
            {{ scope.row.buyCount }}人
          </template>
        </el-table-column>
        <el-table-column label="操作" width="150" align="center">
          <template slot-scope="scope">
            <router-link :to="'/course/info/'+scope.row.id">
              <el-button type="text" size="mini" icon="el-icon-edit">编辑课程信息</el-button>
            </router-link>
            <router-link :to="'/course/chapter/'+scope.row.id">
              <el-button type="text" size="mini" icon="el-icon-edit">编辑课程大纲</el-button>
            </router-link>
            <el-button type="text" @click="deleteCourse(scope.row.id)" size="mini" icon="el-icon-delete">删除</el-button>
          </template>
        </el-table-column>
      </el-table>
      <!-- 分页 -->
      <el-pagination
        :current-page="page"
        :page-size="limit"
        :total="total"
        style="padding: 30px 0; text-align: center;"
        layout="total, prev, pager, next, jumper"
        @current-change="initCourseList"
      />
    </div>
  </div>
</template>

<script>
  import course from "../../../api/course/course";
  import teacher from "../../../api/teacher/teacher";
  import subject from "../../../api/subject/subject";
  import chapter from "../../../api/chapter/chapter";
export default {
  name: "List",
  data() {
    return {
      listLoading: true, // 是否显示loading信息
      list: null, // 数据列表
      total: 0, // 总记录数
      page: 1, // 页码
      limit: 5, // 每页记录数
      searchObj: {
        subjectParentId: '',
        subjectId: '',
        title: '',
        teacherId: ''
      }, // 查询条件
      teacherList: [], // 讲师列表
      subjectNestedList: [], // 一级分类列表
      subSubjectList: [] // 二级分类列表,
    }
  },
  created() {
    // 当页面加载时获取数据
    this.initCourseList()
    // 初始化分类列表
    this.initSubjectList()
    // 获取讲师列表
    this.initTeacherList()
  },
  methods: {
    initCourseList(page = 1) { // 调用api层获取数据库中的数据
      console.log('加载列表')
      // 当点击分页组件的切换按钮的时候，会传输一个当前页码的参数page
      // 解决分页无效问题
      this.page = page
      this.listLoading = true
      course.getCourseList(this.page,this.limit, this.searchObj).then(response => {
        // debugger 设置断点调试
        if (response.success === true) {
          this.list = response.data.data.records
          this.total = response.data.data.total
        }
        this.listLoading = false
      })
    },
    initTeacherList() {
      teacher.getAllList().then(response => {
        this.teacherList = response.data.list
      })
    },
    initSubjectList() {
      subject.getSubjectList().then(response => {
        this.subjectNestedList = response.data.list
      })
    },
    subjectLevelOneChanged(value) {
      for (let i = 0; i < this.subjectNestedList.length; i++) {
        if (this.subjectNestedList[i].id === value) {
          this.subSubjectList = this.subjectNestedList[i].children
          this.searchObj.subjectId = ''
        }
      }
    },
    resetData() {
      this.searchObj = {}
      this.subSubjectList = [] // 二级分类列表
      this.initCourseList()
    },
    deleteCourse(id) {
      this.$confirm('确认删除此数据？', '提示', {
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning'
      }).then(() => {
        course.deleteCourse(id).then(res => {
          this.$message({
            type: 'success',
            message: '成功'
          })
          this.initCourseList()
        })
      }).catch(() => {
        this.$message({
          type: 'info',
          message: '已取消删除'
        });
      });
    }
  }
}
</script>

<style scoped>
  .myClassList .info {
    width: 450px;
    overflow: hidden;
  }
  .myClassList .info .pic {
    width: 150px;
    height: 90px;
    overflow: hidden;
    float: left;
  }
  .myClassList .info .pic a {
    display: block;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }
  .myClassList .info .pic img {
    display: block;
    width: 100%;
  }
  .myClassList td .info .title {
    width: 280px;
    float: right;
    height: 90px;
  }
  .myClassList td .info .title a {
    display: block;
    height: 48px;
    line-height: 24px;
    overflow: hidden;
    color: #00baf2;
    margin-bottom: 12px;
  }
  .myClassList td .info .title p {
    line-height: 20px;
    margin-top: 5px;
    color: #818181;
  }
</style>
